Elongated intracorporal medical device

ABSTRACT

Alternative designs, materials and manufacturing methods for guidewires. Some embodiments pertain to a composite guidewire having proximal and distal section, and a connector adapted and configured for permanently joining the proximal section to the distal section. In some embodiments, at least one of the sections is made of a linear-elastic nickel-titanium alloy. Several alternative guidewire tip constructions and/or designs including methods and techniques of construction are also disclosed.

RELATED APPLICATION

This application is a continuation of co-pending U.S. application Ser.No. 10/376,068, filed Feb. 26, 2003, which is incorporated herein byreference.

FIELD OF TECHNOLOGY

The invention generally pertains to intracorporal medical devices, suchas guidewires, catheters, or the like.

BACKGROUND

A wide variety of medical devices have been developed for intracorporaluse. Elongated medical devices are commonly used in to facilitatenavigation through and/or treatment within the anatomy of a patient.Because the anatomy of a patient may be very tortuous, it is desirableto combine a number of performance features in such devices. Forexample, it is sometimes desirable that the device have a relativelyhigh level of pushability and torqueability, particularly near itsproximal end. It is also sometimes desirable that a device be relativelyflexible, particularly near its distal end. A number of differentelongated medical device structures and assemblies are known, eachhaving certain advantages and disadvantages. However, there is anongoing need to provide alternative elongated medical device structuresand assemblies.

SUMMARY OF SOME EMBODIMENTS

The invention provides several alternative designs, materials andmethods of manufacturing alternative elongated medical device structuresand assemblies.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may be more completely understood in consideration of thefollowing detailed description of various embodiments of the inventionin connection with the accompanying drawings, in which:

FIG. 1 is a partial cross sectional fragmentary view of a guidewire inaccordance with one example embodiment;

FIG. 2 is a cross sectional fragmentary view of another exampleembodiment of a guidewire;

FIG. 3 is a cross sectional view of the ribbon of the guidewire of FIG.1 which is attached to the distal section of the guidewire at a distalattachment point, for example, using solder and radiant heat energy toheat the solder, wherein the dotted lines indicate the area that mightbe heated using radiant heat energy;

FIG. 4 is a cross sectional view of the ribbon of the guidewire of FIG.1 which is attached to the distal section of the guidewire at a distalattachment point, for example, using solder and light source energy toheat the solder, wherein the dotted lines indicate the area that mightbe heated using light source energy;

FIG. 5 is a cross sectional view of the ribbon of the guidewire of FIG.1 which is attached to the distal section of the guidewire at a distalattachment point, for example, using solder and LASER energy to heat thesolder, wherein the dotted lines indicate the area that might be heatedusing LASER energy;

FIG. 6 is a cross sectional view of the proximal section of the ribbonof the guidewire of FIG. 1 prior to attachment to the distal section ofthe guidewire at a proximal attachment point, showing an attachment orcentering ring, and solder material prior to heating;

FIG. 7 is a cross sectional view of the ribbon of the guidewire of FIG.6 during heating, showing the solder material flowing or wicking intothe attachment points to attach the ribbon to the distal portion of theguidewire and to the attachment or centering ring;

FIG. 8 is a cross sectional view of the ribbon of the guidewire of FIG.7 after heating, showing the solder attachment points attaching theribbon to the distal portion of the guidewire and to the attachment orcentering ring, and also showing the coil attached to the centeringring;

FIG. 9 is a cross sectional fragmentary view of an example coilconstruction that can be used in medical devices, the coil constructionincluding an inner coil attached to an outer coil;

FIG. 10 is a cross sectional fragmentary view of another exampleembodiment of a coil construction wherein an inner coil is connected toan outer coil via an intermediate member;

FIG. 11 is a cross sectional fragmentary view of an another example coilconstruction that can be used in medical devices, the coil constructionincluding a first coil attached to a second coil;

FIG. 12 is a cross sectional fragmentary view of an example coilconfiguration that can be used in medical devices, the coilconfiguration including an inner portion and an outer portion;

FIG. 13 is a cross sectional fragmentary view of a tip construction of aguidewire including the coil configuration of FIG. 12;

FIG. 14 is a cross sectional fragmentary view of an example coil thatcan be used in medical devices, the coil including a wire including aninner portion made of a first material and an outer portion made of asecond material;

FIG. 15 is a partial cross sectional fragmentary view of a guidewire inaccordance with another example embodiment.

While the invention is amenable to various modifications and alternativeforms, specifics thereof have been shown by way of example in thedrawings and will be described in detail. It should be understood,however, that the intention is not to limit the invention to theparticular embodiments described. On the contrary, the intention is tocover all modifications, equivalents, and alternatives falling withinthe spirit and scope of the invention.

DETAILED DESCRIPTION OF SOME EXAMPLE EMBODIMENTS

For the following defined terms, these definitions shall be applied,unless a different definition is given in the claims or elsewhere inthis specification.

All numeric values are herein assumed to be modified by the term“about,” whether or not explicitly indicated. The term “about” generallyrefers to a range of numbers that one of skill in the art would considerequivalent to the recited value (i.e., having the same function orresult). In many instances, the terms “about” may include numbers thatare rounded to the nearest significant figure.

Weight percent, percent by weight, wt %, wt-%, % by weight, and the likeare synonyms that refer to the concentration of a substance as theweight of that substance divided by the weight of the composition andmultiplied by 100.

The recitation of numerical ranges by endpoints includes all numberswithin that range (e.g. 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and5).

As used in this specification and the appended claims, the singularforms “a”, “an”, and “the” include plural referents unless the contentclearly dictates otherwise. As used in this specification and theappended claims, the term “or” is generally employed in its senseincluding “and/or” unless the content clearly dictates otherwise.

The following detailed description should be read with reference to thedrawings in which similar elements in different drawings are numberedthe same. The drawings, which are not necessarily to scale, depictillustrative embodiments and are not intended to limit the scope of theinvention. For example, although discussed with specific reference toguidewires in the particular embodiments described herein, the inventionmay be applicable to a variety of medical devices that are adapted to beadvanced into the anatomy of a patient through an opening or lumen. Forexample, certain aspects of the invention may be applicable to fixedwire devices, catheters (e.g. balloon, stent delivery, etc.) driveshafts for rotational devices such as atherectomy catheters and IVUScatheters, endoscopic devices, laparoscopic devices, embolic protectiondevices, spinal or cranial navigational or therapeutic devices, andother such devices.

Refer now to FIG. 1 which a is a partial cross sectional fragmentaryview of a guidewire 10 including a proximal guidewire section 14 and adistal guidewire section 16. The proximal section 14 includes a distalend 24 and a proximal end 25, and the distal section 16 includes aproximal end 26 and a distal end 27. In this embodiment, the guidewire10 includes a connection 20 joining the proximal guidewire section 14and the distal guidewire section 16. The embodiment of FIG. 1 utilizes ajoint 12 including a tubular connector 18. In some other embodiments,the guidewire 10 can include a shaft or core portion that can be onecontinuous member, for example, the proximal guidewire section 14 and adistal guidewire section 16 may be continuous with one another and,collectively, define a continuous shaft or core. In some otherembodiments, the guidewire 10 can include a shaft or core portion thatincludes a plurality of sections connected by joints. As used herein,the proximal section 14 and the distal section 16 may generically referto any two adjacent guidewire sections along any portion of theguidewire.

Those of skill in the art and others will recognize that the materials,structure, and dimensions of the proximal/distal guidewire sections14/16 are dictated primary by the desired characteristics and functionof the final guidewire, and that any of a broad range of materials,structures, and dimensions can be used.

For example, the proximal and distal guidewire sections 14/16 may beformed of any materials suitable for use, dependent upon the desiredproperties of the guidewire. Some examples of suitable materials includemetals, metal alloys, polymers, or the like, or combinations or mixturesthereof. Some examples of suitable metals and metal alloys includestainless steel, such as 304V, 304L, and 316L stainless steel; alloysincluding nickel-titanium alloy such as linear elastic or superelastic(i.e. pseudoelastic) nitinol; nickel-chromium alloy;nickel-chromium-iron alloy; cobalt alloy; tungsten or tungsten alloys;MP35-N (having a composition of about 35% Ni, 35% Co, 20% Cr, 9.75% Mo,a maximum 1% Fe, a maximum 1% Ti, a maximum 0.25% C, a maximum 0.15% Mn,and a maximum 0.15% Si); hastelloy; monel 400; inconel 625; or the like;or other suitable material, or combinations or alloys thereof. In someembodiments, it is desirable to use metals, or metal alloys that aresuitable for metal joining techniques such as welding, soldering,brazing, crimping, friction fitting, adhesive bonding, etc.

The word nitinol was coined by a group of researchers at the UnitedStates Naval Ordinance Laboratory (NOL) who were the first to observethe shape memory behavior of this material. The word nitinol is anacronym including the chemical symbol for nickel (Ni), the chemicalsymbol for titanium (Ti), and an acronym identifying the Naval OrdinanceLaboratory (NOL).

Within the family of commercially available nitinol alloys, is acategory designated “linear elastic” which, although is similar inchemistry to conventional shape memory and superelastic (i.e.pseudoelastic) varieties, exhibits distinct and useful mechanicalproperties. By skilled applications of cold work, directional stress,and heat treatment, the wire is fabricated in such a way that it doesnot display a substantial “superelastic plateau” or “flag region” in itsstress/strain curve. Instead, as recoverable strain increases, thestress continues to increase in an essentially linear relationship untilplastic deformation begins. In some embodiments, the linear elasticnickel-titanium alloy is an alloy that does not show anymartensite/austenite phase changes that are detectable by DSC and DMTAanalysis over a large temperature range.

For example, in some embodiments, there is no martensite/austenite phasechanges detectable by DSC and DMTA analysis in the range of about −60°C. to about 120° C. The mechanical bending properties of such materialare therefore generally inert to the effect of temperature over thisvery broad range of temperature. In some particular embodiments, themechanical properties of the alloy at ambient or room temperature aresubstantially the same as the mechanical properties at body temperature.In some embodiments, the use of the linear elastic nickel-titanium alloyallows the guidewire to exhibit superior “pushability” around tortuousanatomy.

In some embodiments, the linear elastic nickel-titanium alloy is in therange of about 50 to about 60 weight percent nickel, with the remainderbeing essentially titanium. In some particular embodiments, thecomposition is in the range of about 54 to about 57 weight percentnickel. One example of a suitable nickel-titanium alloy is FHP-NT alloycommercially available from Furukawa Techno Material Co. of Kanagawa,Japan. Some examples of suitable nickel-titanium alloys include thosedisclosed in U.S. Pat. Nos. 5,238,004 and 6,508,803, which areincorporated herein by reference. In some other embodiments, asuperelastic alloy, for example a superelastic nitinol can be used toachieve desired properties.

The entire guidewire 10 can be made of the same material, or in someembodiments, can include portions or sections, for example,proximal/distal guidewire sections 14/16, that are made of differentmaterials. In some embodiments, the material used to construct differentportions of the guidewire 10 can be chosen to impart varying flexibilityand stiffness characteristics to different portions of the wire. Forexample, in some embodiments, the proximal guidewire section 14 may beformed of relatively stiff material such as straightened 304v stainlesssteel wire. Alternatively, proximal portion 14 may be comprised of ametal or metal alloy such as a nickel-titanium alloy, nickel-chromiumalloy, nickel-chromium-iron alloy, cobalt alloy, or other suitablematerial. In general, the material used to construct proximal portion 14may be selected to be relatively stiff for pushability andtorqueability.

In some embodiments, the distal guidewire section 16 may be formed of arelatively flexible material such as a straightened super elastic (i.e.pseudoelastic) or linear elastic alloy (e.g., nickel-titanium), oralternatively, a polymer material, such as a high performance polymer.Alternatively, distal portion 16 may include a metal or metal alloy suchas stainless steel, nickel-chromium alloy, nickel-chromium-iron alloy,cobalt alloy, or other suitable material. In general, the material usedto construct distal portion 16 may be selected to be relatively flexiblefor trackability.

In at least some embodiments, portions or all of the proximal/distalguidewire sections 14/16, or other structures included within theguidewire 10 may also be doped with, coated or plated with, made of, orotherwise include a radiopaque material. Radiopaque materials areunderstood to be materials capable of producing a relatively brightimage on a fluoroscopy screen or another imaging technique during amedical procedure. This relatively bright image aids the user ofguidewire 10 in determining its location. Some examples of radiopaquematerials can include, but are not limited to, gold, platinum,palladium, tantalum, tungsten alloy, polymer material loaded with aradiopaque filler, and the like, or combinations or alloys thereof.

In some embodiments, a degree of MRI compatibility is imparted intoguidewire 10. For example, to enhance compatibility with MagneticResonance Imaging (MRI) machines, it may be desirable to make theproximal/distal guidewire sections 14/16, or other portions of guidewire10, in a manner that would impart a degree of MRI compatibility. Forexample, the proximal/distal guidewire sections 14/16, or portionsthereof, may be made of a material that does not substantially distortthe image and create substantial artifacts (artifacts are gaps in theimage). Certain ferromagnetic materials, for example, may not besuitable because they may create artifacts in an MRI image. Theproximal/distal guidewire sections 14/16, or portions thereof, may alsobe made from a material that the MRI machine can image. Some materialsthat exhibit these characteristics include, for example, tungsten,Elgiloy, MP35N, nitinol, and the like, and others, or combinations oralloys thereof.

The length of proximal/distal guidewire sections 14/16 (and/or thelength of guidewire 10) are typically dictated by the length andflexibility characteristics desired in the final medical device. Forexample, proximal section 14 may have a length in the range of about 20to about 300 centimeters or more, the distal section 16 may have alength in the range of about 3 to about 50 centimeters or more, and theguidewire 10 may have a total length in the range of about 25 to about350 centimeters or more. It can be appreciated that alterations in thelength of sections 14/16 and guidewire 10 can be made without departingfrom the spirit of the invention.

Proximal/distal guidewire sections 14/16 can have a solid cross-section,but in some embodiments, can have a hollow cross-section. In yet otherembodiments, guidewire sections 14/16 can include combinations of areashaving solid cross-sections and hollow cross sections. Moreover,guidewire sections 14/16 can be made of rounded wire, flattened ribbon,or other such structures having various cross-sectional geometries. Thecross-sectional geometries along the length of guidewire sections 14/16can also be constant or can vary. For example, FIG. 1 depicts guidewiresections 14/16 as having a generally round cross-sectional shape. It canbe appreciated that other cross-sectional shapes or combinations ofshapes may be utilized without departing from the spirit of theinvention. For example, the cross-sectional shape of guidewire sections14/16 may be oval, rectangular, square, polygonal, and the like, or anysuitable shape.

As shown in FIG. 1, guidewire sections 14/16 may include one or moretapers or tapered regions. The tapered regions may be linearly tapered,tapered in a curvilinear fashion, uniformly tapered, non-uniformlytapered, or tapered in a step-wise fashion. The angle of any such taperscan vary, depending upon the desired flexibility characteristics. Thelength of the taper may be selected to obtain a more (longer length) orless (shorter length) gradual transition in stiffness. It can beappreciated that essentially any portion of guidewire 10 and/orguidewire sections 14/16 may be tapered and the taper can be in eitherthe proximal or the distal direction.

As shown in FIG. 1, the guidewire sections 14/16 may include one or moreportions where the outside diameter is narrowing, and portions where theoutside diameter remains essentially constant. The number, arrangement,size, and length of the narrowing and constant diameter portions can bevaried to achieve the desired characteristics, such as flexibility andtorque transmission characteristics.

The tapered and constant diameter portions of the tapered region may beformed by any one of a number of different techniques, for example, bycenterless grinding methods, stamping methods, and the like. Thecenterless grinding technique may utilize an indexing system employingsensors (e.g., optical/reflective, magnetic) to avoid excessive grindingof the connection. In addition, the centerless grinding technique mayutilize a CBN or diamond abrasive grinding wheel that is well shaped anddressed to avoid grabbing core wire during the grinding process. In someembodiments, distal shaft member 20 can be centerless ground using aRoyal Master HI-AC centerless grinder. Some examples of suitablegrinding methods are disclosed in U.S. Patent Pub. No. 2004/0142643,which is herein incorporated by reference.

The narrowing and constant diameter portions as shown in FIG. 1 are notintended to be limiting, and alterations of this arrangement can be madewithout departing from the spirit of the invention. One of skill willrecognize that a guidewire core wire can have a profile different fromthat illustrated in FIG. 1.

In the embodiment shown in FIG. 1, the distal guidewire section 16includes three constant diameter regions 31, 33, and 35, interconnectedby two tapering regions 37 and 39. The constant diameter regions 31, 33,and 35 and tapering regions 37 and 39 are disposed such that the distalguidewire section 16 includes a geometry that decreases in crosssectional area toward the distal end thereof. In some embodiments, theseconstant diameter regions 31, 33, and 35 and tapering regions 37 and 39are adapted and configured to obtain a transition in stiffness, andprovide a desired flexibility characteristic. Also in some embodiments,portions of the guidewire section 16 can be flattened, for example, toprovide for desired flexibility characteristics, or to provide anattachment point for other structure. For example, constant diameterportion 35 could include a portion thereof that is flattened.

The distal guidewire section 16 also includes tapered portion 41 andconstant diameter portion 43 near its proximal end. This reduction indiameter near the proximal end is configured to accommodate theconnector member 18 in this particular embodiment, as will be discussedin more detail below.

In the embodiment shown in FIG. 1, the proximal section 14 includes aproximal constant diameter portion 45, a distal constant diameterportion 47, and a taper portion 49 disposed there between. Thisreduction in diameter near the distal end the proximal section 14 isalso configured to accommodate the connector member 18 in thisparticular embodiment, as will be discussed in more detail below.

It is to be understood that a broad variety of materials, dimensions andstructures can be used to construct suitable embodiments, depending onthe desired characteristics. The following examples of some dimensionsare included by way of example only, are not intended to be limiting,and other dimensions out of the following ranges can be used.

In some example embodiments, the distal section 16 of the guidewire 10can have a length in the range of about 3 to about 25 inches. Theconstant diameter regions 31, 33, and 35, can have outer diameters inthe range of about 0.01 to about 0.015, about 0.005 to about 0.012 andabout 0.001 to about 0.005 inches respectively, and lengths in the rangeof about 1 to about 10, about 1 to about 10 and about 0.1 to about 2inches, respectively. The tapering regions 37 and 39 can have lengths inthe range of about 0.5 to about 5, and about 0.5 to about 5.0 inches,respectively, and are generally linearly tapered. Additionally, theconstant diameter portion 43 can have outer diameters in the range ofabout 0.005 to about 0.012 inches, and a length in the range of about0.02 to about 1.5 inches. The tapered portion 41 can have a length inthe range of about 0.02 to about 1.0 inch, and can be generally linearlytapered.

In some embodiments, as discussed above, a portion of the constantdiameter portion 35 can be flattened, for example, the distal most about0.05 to about 1.0 inch of the constant diameter portion 35 can beflattened to define generally parallel opposed surfaces, and to have athickness in the range of about 0.0005 to about 0.0025 inches.

Also in some example embodiments, the proximal section 14 of theguidewire 10 can have a length in the range of about 30 to about 150inches. The constant diameter regions 45, and 47 can have outerdiameters in the range of about 0.01 to about 0.015 and about 0.005 toabout 0.012 inches, respectively, and lengths in the range of about 30to about 150, and about 0.02 to about 1.5 inches, respectively. Thetapering section 49 can have a length in the range of about 0.02 toabout 1 inch, and can be generally linearly tapered.

In some particular embodiments, the proximal guidewire section 14 isformed from a stainless steel wire, and the distal guidewire section 16is formed from a linear elastic nitinol wire.

The distal end 24 of the proximal portion 14 and the proximal end 26 ofdistal portion 16 (i.e., the joined ends) may form a joint 12. Somemethods and structures that can be used to interconnect different shaftsections are disclosed in U.S. Pat. Nos. 6,918,882, and 7,074,197, whichare incorporated herein by reference.

In some embodiments, the joined ends 24/26 are spaced, as shown inFIG. 1. In some embodiments, the joined ends 24/26 can be spaced adistance in the range of about 0 to about 1.5 inches within theconnector member 18. Alternatively, the joined ends 24/26 may form atouching but joint, an overlapping tapered joint 12, an overlappingjoint 12 that is not tapered, or the like. The end portions 24/26 mayhave a uniform profile (diameter), a bulbous portion for purposes ofmechanical interlocking and the like, or a helical form for purposes ofmechanical interlocking or the like. In embodiments where the endportions 24/26 overlap to form an overlapping joint, the overlappingjoint can function to blend the stiffness of proximal portion 14 anddistal portion 16 by combining the properties of each end section 24/26making up the cross section of the overlapping joint. In someembodiments, the joint 12 can form a flexibility transition region thathas a relative flexibility that is between the flexibility of the distalend 24 of the proximal portion 14 and the flexibility of the proximalend 26 of the distal portion 16.

As mentioned previously, the proximal guidewire section 14 and thedistal guidewire section 16 may be formed of different materials (i.e.,materials having different moduli of elasticity) resulting in adifference in flexibility. For example, the proximal guidewire section14 may be formed of stainless steel wire and the distal guidewiresection 16 may be formed of nickel-titanium alloy wire, both having thesame dimensions near the joint, resulting in a 3:1 difference in elasticmodulus. Such a difference in elastic modulus (i.e., flexibility) mayresult in a stress concentration point during flexure and/or torsionthat may have a tendency to kink and fracture. By virtue of the gradualtransition in stiffness provided in some embodiments by the joint 12,stress is distributed along the entire length of the connection 20thereby decreasing the probability that guidewire 10 may kink at thejunction.

A gradual transition in stiffness may also allow the connection 20 to belocated further distally. According to this embodiment, the distalportion 16 may be manufactured to be shorter than proximal portion 14.Including a relatively long proximal section 14 may advantageouslyincrease the torquability and pushability of the guidewire 10. Althoughonly one connection 20 is shown, additional connections 20 may be usedto connect other guidewire sections of varying stiffness.

The connector 18 may comprise a tubular structure such as a hypotube asshown or a coiled wire. The connector 18 may have an inside diametersized appropriately to receive the ends 24/26 of the proximal portion 14and the distal portion 16, and an outside diameter sufficient toaccommodate a final grinding procedure. In some example embodiments, theconnector 18 can have an inner diameter in the range of about 0.004 toabout 0.02 inches, and an outer diameter in the range of about 0.01 toabout 0.02 inches. The final diameter of the guidewire 10 and theconnector 18 may be in the range of 0.010 to 0.018 inches, for example.By way of example, not limitation, the connector 18 may have a length ofabout 0.03 to 3.0 inches. However, in some other embodiments, this typeof construction can be applied to wires of larger diameter intended, forexample, for peripheral intervention purposes. Such wires could range aslarge as 0.035 inches in diameter or larger, and therefore have anextended length connector and correspondingly longer overlappingsections. The diameters given, as with the other specific dimensionalinformation given herein, are by way of example only.

In some embodiments, the lateral flexibility, bendability or other suchcharacteristics of the connector 18 can be achieved or enhanced in anumber of ways. For example, the materials selected for the connector 18may be chosen so that the connector 18 has a desired lateralflexibility. For example, in some embodiments, it may be desirable thatthe connector 18 has a greater lateral flexibility than the lateralflexibilities of proximal guidewire section 14 adjacent distal end 24and distal guidewire section 16 adjacent proximal end 26. For example,the connector 18 may be formed of materials having a different modulusof elasticity than the adjacent portions of the guidewire members 14/16,resulting in a difference in flexibility.

In addition to, or as an alternative to material composition, thedesired lateral flexibility or bending characteristics can be impartedor enhanced by the structure of the connector 18. For example, aplurality of grooves, cuts, slits, or slots can be formed in a tubularconnector 18. Such structure may be desirable because they may allowconnector 18 to be bendable as well as transmit torque and pushingforces from proximal section 14 to distal section 16. The cuts or slotsor grooves can be formed in essentially any known way. For example,cuts, grooves or slots can be formed by mechanical methods, such asmicro machining, saw cutting, LASER cutting, chemically etching,treating or milling, casting, molding, other known methods, and thelike. In some embodiments, cuts, grooves, or slots can completelypenetrate connector 18. In other embodiments, cuts, grooves, or slotsmay only partially extend into connector 18, or include combinations ofboth complete and partial cuts.

The arrangement of such cuts, grooves, or slots may vary. For example,the cuts, grooves, or slots may be formed such that one or more spines,splines, or beams are formed in the tubular connector 18. Such spines orbeams could include portions of the tubular member that remain after thecuts or slots are formed in the body of the tubular member. Such spinesor beams can act to maintain a relatively high degree of tortionalstiffness, while maintaining a desired level of lateral flexibility. Insome embodiments, some adjacent cuts or slots can be formed such thatthey include portions that overlap with each other about thecircumference of the tube. In other embodiments, some adjacent slots orcuts can be disposed such that they do not necessarily overlap with eachother, but are disposed in a pattern that provides the desired degree oflateral flexibility.

Additionally, the size, shape, spacing, or orientation of the cuts orslots, or in some embodiments, the associated spines or beams, can bevaried to achieve the desired lateral flexibility and/or tortionalrigidity characteristics of the connector 18. The number or density ofthe cuts or slots along the length of the connector 18 may vary,depending upon the desired characteristics. For example, the number orproximity of slots to one another near the midpoint of the length of theconnector 18 may be high, while the number or proximity of slots to oneanother near either the distal or proximal end of the connector 18, orboth, may be relatively low, or vice versa. Collectively, thisdescription illustrates that changes in the arrangement, number, andconfiguration of slots may vary without departing from the scope of theinvention. Some additional examples of arrangements of cuts or slotsformed in a tubular body are disclosed in U.S. Pat. Nos. 6,428,489,6,579,246, and in U.S. Patent Pub. No. 2004/0167437, all of which areincorporated herein by reference.

The connector 18 may be made of or include a metal, metal alloy,polymer, metal-polymer composite, or the like, as discussed above withregard to the guidewire sections 14/16, and may include radiopaquematerials or include materials or structure to impart a degree of MRIcompatibility, as discussed above with regard to the guidewire sections14/16.

Some types of alloys are particularly suitable for connector 18 for somepurposes, for example, for connecting a stainless steel proximal section14 and a nickel titanium alloy distal section 16, or visa-versa. Anexample is a nickel-chromium-iron alloy designated UNS N06625 and isavailable under the trade name INCONEL 625, which advantageously weldsto both stainless steels and nickel-titanium alloys. INCONEL 625 wiremay be obtained from California Fine Wire Company of Grover Beach,Calif. Another example of a suitable alloy which welds to both stainlesssteels and nickel-titanium alloys is designated UNS 10276 and isavailable under the trade name ALLOY C276 from Fort Wayne MetalsResearch Products Corporation of Fort Wayne, Ind. Another example of asuitable alloy which welds to both stainless steels and nickel-titaniumalloys is of the Hastelloy family and an example of which is availableunder the trade name ALLOY B2 from Fort Wayne Metals Research ProductsCorporation of Fort Wayne, Ind. In some embodiments, where for example,a welding process is used to connect the connector 18, for example, to astainless steels proximal section 14 and a nickel-titanium proximalsection 6, it can be beneficial to use an alloy material for theconnector 18 that can be welded to both stainless steel and a nickeltitanium alloy.

To manufacture the connection 20 of the guidewire 10, the ends 24/26 ofthe proximal and distal guidewire sections 14/16 may be ground to formthe desired shape to accommodate the connector. For example, a recessstep, such as constant diameter portions 43/47 and taper portions 41/49may be ground or otherwise formed into the proximal and distal guidewiresections 14/16 to accommodate the connector tube 18. If a connector tube18 is not to be used, such a recess step need not be ground.

For the embodiments utilizing a connector tube 18, the connector tube 18is positioned over one of the ends 24/26 of the proximal and distalguidewire sections 14/16. The proximal and distal guidewire sections14/16 and the connector tube 18 may be bonded, welded (e.g., resistanceor LASER welded), soldered (e.g. LASER diode soldering), brazed, orotherwise connected by a suitable technique depending on the materialselected for each component. Additionally, in some other exampleembodiments, securing the connector 18 to the proximal and distalsections 14/16 may include the use of a connector and/or an expandablealloy, for example, a bismuth alloy. Some examples of methods,techniques and structures that can be used to interconnect differentportions of a guidewire using such expandable material are disclosed ina U.S. Patent Publication No. 2004/0167441, and which is herebyincorporated by reference. Alternatively, the ends 24/26 and theconnector tube 18 may be crimped together or may be sized to establish afriction fit therebetween. If a connector tube 18 is not used, the ends24/26 may be bonded, welded (e.g., resistance or LASER welded),soldered, brazed, or otherwise connected, using a connector material.Connector material may be the same as or similar to the material of theconnector 18. In all cases, because the connection 20 may reside withina catheter lumen or within the anatomy during use, it is preferred thata permanent connection (as opposed to a releasable connection) be used.

In some particular embodiments, the connector 18 is welded to proximaland distal guidewire sections 14/16. It is to be appreciated thatvarious welding processes can be utilized. In general, welding refers toa process in which two materials such as metal or metal alloys arejoined together by heating the two materials sufficiently to at leastpartially melt adjoining surfaces of each material. A variety of heatsources can be used to melt the adjoining materials. Examples of weldingprocesses that can be suitable in some embodiments include LASERwelding, resistance welding, TIG welding, microplasma welding, electronbeam, and friction or inertia welding.

LASER welding equipment which may be suitable in some applications iscommercially available from Unitek Miyachi of Monrovia, Calif. andRofin-Sinar Incorporated of Plymouth, Mich. Resistance welding equipmentwhich may be suitable in some applications is commercially availablefrom Palomar Products Incorporated of Carlsbad, Calif. and PolarisElectronics of Olathe, Kans. TIG welding equipment which may be suitablein some applications is commercially available from WeldlogicIncorporated of Newbury Park, Calif. Microplasma welding equipment whichmay be suitable in some applications is commercially available fromProcess Welding Systems Incorporated of Smyrna, Tenn.

In some embodiments, LASER or plasma welding can be used to secure theconnector 18 and the proximal and distal guidewire sections 14/16securely together. In LASER welding, a light beam is used to supply thenecessary heat. LASER welding can be beneficial in the processescontemplated by the invention, as the use of a LASER light heat sourcecan provide pinpoint accuracy. It should also be understood that suchLASER welding can also be used to attach other components of theguidewire, as discussed below.

Additionally, in some embodiments, LASER energy can be used as the heatsource for soldering, brazing, or the like for attaching differentcomponents or structures of the guidewire together. Again, the use of aLASER as a heat source for such connection techniques can be beneficial,as the use of a LASER light heat source can provide pinpoint accuracy.One particular example of such a technique includes LASER diodesoldering.

In some embodiments, the connection can extend around the entirecircumference of the connector 18 and the proximal and distal guidewiresections 14/16. In some other embodiments, however, one or more spacedconnection points can be made around the circumference of the proximaland distal guidewire sections 14/16. The use of certain attachmenttechniques, for example laser welding or laser diode soldering, or thelike, can be useful in making connections around only a portion of thecircumference because they tend to allow the accuracy needed to makesuch connections.

Once connected, the connector tube 18 and the proximal and distalguidewire sections 14/16 can be centerless ground or otherwise shaped orformed as desired to provide the desired characteristics, for example, asmooth and uniform profile across the connection 20, or to straightenout small misalignments between the proximal and distal guidewiresections 14/16. Other portions of the guidewire 10 may be ground as wellto provide the desired tapers and changes in diameter.

Once finally formed or ground, in some embodiments, a flexible coil tipand/or a polymer jacket tip (optionally covering connection 20) orcombination thereof, and other such structure, such as radiopaquemarkers, safety and/or shaping ribbons (coiled or uncoiled), and thelike, may be placed on the guidewire 10. Some examples of additionalcomponents and tip constructions are disclosed in U.S. Pat. Nos.6,918,882, and 7,074,197, which are incorporated herein by reference.Additionally, in some embodiments, a coating, for example a lubricious(e.g., hydrophylic) or other type of coating may be applied to all orportions of the guidewire. Different coatings can be applied todifferent sections of the guidewire. Some examples of such coatings andmaterials and methods used to create such coatings can be found in U.S.Pat. Nos. 6,139,510 and 5,772,609, which are incorporated herein byreference.

For example, the embodiment in FIG. 1 includes a wire or ribbon 58 thatis attached adjacent the distal end 27 of the distal section 16, andextends distally of the distal end 27. In some embodiments, the wire orribbon 58 can be a fabricated or formed wire structure, for example acoiled wire. In the embodiment shown however, the ribbon 58 is agenerally straight ribbon that overlaps with and is attached to thedistal end 27 of the distal section 16.

The ribbon 58 can be made of any suitable material and sizedappropriately to give the desired characteristics, such as strength andflexibility characteristics. Some examples of suitable materials includemetals, metal alloys, polymers, and the like, and may include radiopaquematerials or include materials or structure to impart a degree of MRIcompatibility, as discussed above in relation to the proximal and distalguidewire sections 14/16, and in relation to the connector 18.

The following examples of some dimensions are included by way of exampleonly, and are not intended to be limiting.

In some embodiments, the ribbon 58 is a flattened ribbon having a widthin the range of about 0.002 to about 0.008 inches, a thickness in therang of about 0.0005 to about 0.003 inches, and a length in the range ofabout 0.25 to about 3.0 inches. In some embodiments, the ribbon 58overlaps with the distal section 16 by a length in the range of about0.25 to about 2.0 inches, and includes a distal portion that extendsdistally beyond the distal section 16 by a length in the range of about0.1 to about 2.0 inches.

The ribbon 58 can be attached to the distal section 16 using anysuitable attachment technique. Some examples of attachment techniquesinclude soldering, brazing, welding, adhesive bonding, crimping, or thelike. In some embodiments, the ribbon or wire 58 can function as ashaping structure or a safety structure. The distal end of the ribbon 58can be free of attachment, or can be attached to another structure, forexample a tip portion 69, for example, a rounded tip portion. The tipportion 69 can be made or formed of any suitable material, for example asolder tip, a polymer tip, a welded tip, and the like, using suitabletechniques.

In the embodiment shown in FIG. 1, the ribbon 58 is attached to thedistal section 16 adjacent the distal end 27 thereof at two attachmentpoints, 59 and 61. Attachment point 59 is disposed adjacent constantdiameter region 35, which may or may not be flattened, as discussedabove. In some embodiments, the attachment point 59 is disposed at thevery distal end 27 of the distal section 16, while in other embodiments,the attachment point can be spaced more proximally form the very distalend 27. In some embodiments, attachment adjacent the very distal end 27is used such that the distal end 27 of the section 16 and the ribbon canflex as one connected or integral unit. Such an arrangement can providefor desirable trackability characteristics, and can provide fordesirable tip resiliency characteristics.

Attachment point 61 is disposed adjacent tapering region 39. It shouldbe understood, however, that these attachment points and attachmenttechniques are given by way of example only, and that the ribbon can beattached at different locations and by using more or fewer attachmentpoints, and a variety of attachment techniques, as desired, withoutparting from the spirit and scope of the invention.

Refer now to FIGS. 3-5 for a discussion of some particular attachmenttechniques that can be used. FIGS. 3-5 are close up cross sectionalviews of the guidewire of FIG. 1 about attachment point 59. In each ofthese Figures, the ribbon 58 is attached to the constant diameter region35 adjacent the distal end 27 of the distal section 16 using a heatactivated attachment material, for example a solder material 63, abrazing material, or other such material.

FIG. 3 is included to illustrate the use of a broad heat source, forexample, a radiant heat source, to heat and activate the solder material63 to make the connection. The dotted lines indicate the area that mightbe heated using such radiant heat energy. As can be seen, the entirearea surrounding the attachment point 59 would be heated. In someembodiments, this can be undesirable. For example, if some of thecomponents of the guidewire are heat sensitive materials, the heat mayadversely affect the characteristics of the material. One example ofsuch materials include some nickel titanium alloys, which if exposed toundue heat above a certain point, may undergo a phase change, or mayanneal, which may effect the desired properties of the material.

FIG. 4 is similar to FIG. 3, but is included to illustrate the use of anarrower, or more controlled heat source, for example, light sourceenergy, to heat the solder 63, wherein the dotted lines indicate thearea that might be heated using light source energy. As can be seen,although the area affected is narrower than using a radiant heat source,as describe with reference to FIG. 3, the light source energy may stillundesirably heat areas surrounding the attachment point 59.

FIG. 5 is similar to FIGS. 3 and 4, but is included to illustrate theuse of an even narrower, or more controlled heat source, for example, aLASER energy source, to heat the solder 63, wherein the dotted linesindicate the area that might be heated using LASER source energy. As canbe seen, the area affected is narrower than using a radiant heat source,or light source energy. Therefore, the use of LASER energy may bedesirable to avoid undesirably heating larger areas surrounding theattachment point 59. The use of a LASER as a heat source in soldering,brazing, and the like, can be beneficial in the processes contemplatedby the invention, as the use of a LASER light heat source can providepinpoint accuracy. It should also be understood that such LASERsoldering or brazing, or the like, can also be used to attach othercomponents of the guidewire. One additional example of a process thatuses LASER energy is diode soldering, which can also be used.

In some embodiments, the structures being connected can be pre-treatedand/or pre-coated with a suitable attachment material prior toattachment. For example, the ribbon 58, or portions thereof, and/or thedistal section 16, or portions thereof, or both, can be cleaned ortreated to remove impurities or oxides. This can be useful, especiallywhen one or both of the materials being connected is a difficultmaterial to solder or braze to, such as some nickel titanium alloys.Some examples of such treatments include acid baths or washes, fluxing,pickling, pre-tinning, pre-plating (i.e. plating with another material)and the like. In some embodiments, one or both of the surfaces to beconnected can be cleaned and pre-plated with another metallic material,for example, a nickel plating. In some embodiments, the surface to besoldered or brazed is treated with a molten alkali metal hydroxide, andthen pretreated, or “pre-tinned” with a suitable solder or brazingmaterial. It should also be understood within the context of thisdisclosure that when a heat activated attachment material, such assolder or brazing material, is used to connect two components, such heatactivated attachment material can be predisposed on the components beingconnected using such processes or treatments, or can be separatelydisposed or added to make the connection. Therefore, the heat activatedattachment material used for making such connections can come formeither source (“pre-tinned” or “added”), or from both sources. The heatactivated attachment material can include any suitable, brazingmaterial, or the like. Some examples of suitable solder or brazingmaterial include, but are not limited to, tin based materials, forexample, gold-tin solder, silver-tin solder, and the like, and manyothers.

Refer now to FIGS. 6-8 for a discussion of some additional particularattachment techniques that can be used. FIGS. 6 and 7 are close up crosssectional views of the distal guidewire section 16 of FIG. 1 atattachment point 61 prior to and during an attachment procedure. FIG. 8is a close up cross sectional view of the distal guidewire section 16 ofFIG. 1 at attachment point 61 after attachment of the ribbon 58 to thedistal section 16. In each of these Figures, the ribbon 58 is beingattached to the tapering region 39 adjacent the distal end 27 of thedistal section 16 using a heat activated attachment material, forexample a solder 63, a brazing material, or other such material.Additionally, an attachment or centering ring 65 is also being attachedto the tapering region 39.

FIG. 6 shows an attachment or centering ring 65 that is disposed aboutthe distal section 16, and the ribbon 58 is disposed between thecentering ring 65 and the distal section 16. The centering ring 65 canbe a generally tubular member that is adapted or configured to fit overa portion of the distal section 16, and in at least some embodiments, isadapted or configured to attach to the ribbon 58 and the distal section16. Additionally, the centering ring 65 can be adapted and configured toattach to an outer member, such as a coil 80, as discussed in moredetail below. In some embodiments, prior to attachment, as shown in FIG.6, heat activated bonding or filler material, such as solder material63, can be disposed adjacent to the centering ring 65. For example,solder material 63 can be disposed about the distal section 16, adjacentto the centering ring 65 and the ribbon 58. It should be understoodhowever, that in other embodiments, the solder material 63 can bedisposed or located at a different location than shown, for example,adjacent the proximal side of the centering ring 65, or alternatively,could be disposed in the desired attachment positions between themembers to be connected prior to connection.

As shown in FIG. 7, the solder material 63 can then be heated using anappropriate heat source, and it will begin to flow into an attachmentposition between the ribbon and the distal section 16, and/or betweenthe ribbon 58 and the centering ring 65, and/or between the distalsection 16 and the centering ring 65, or all of the above positions.Some examples of suitable heat sources for use in soldering or brazingare described above. However, in some embodiments, LASER energy is usedas the heat source to provide for accuracy of heating, and to avoidundesirable heating of structures adjacent the attachment points.

FIG. 8 shows the solder material 63 disposed in attachment positionsthat connect the ribbon 58 to the distal section 16, connect the ribbon58 to the centering ring 65, and connect the distal section 16 to thecentering ring 65. FIG. 8 also shows a coil 80 that has been attached tothe centering ring 65, as will be discussed in more detail below.

It should be understood that the components being attached using such atechnique, prior to attachment, can undergo treatments such as acidbaths or washes, fluxing, pickling, pre-tinning, and the like, asdescribed above.

It should also be understood that the above described attachmenttechniques are merely illustrative, and that other suitable attachmenttechniques or structures can be used. Additionally, the attachmenttechniques described above can be used at other locations along thelength of the guidewire, or can be used to attach other components ofthe guidewire to each other. For example, a ring, such as attachment orcentering ring 65, can be used to attach coils, ribbons, braids, wires,or the like, or other such structures to the proximal or distalguidewire sections 14/16. Additionally, the soldering or brazingtechniques, for example, the use of LASER energy as the heat source, canbe used in attaching additional structures to proximal or distalguidewire sections 14/16.

The embodiment in FIG. 1 also includes a coil 80 disposed about at leasta portion of the proximal and/or distal guidewire sections 14/16. In theparticular embodiment shown, the coil 80 can extend about the distalsections 16 from a point adjacent the tapering region 37 distally to apoint beyond the distal most portion of the distal section 16. The coil80 is attached to the distal guidewire section 16 at its proximal end 81at attachment point 83 using any suitable attachment technique, forexample soldering, brazing, welding, adhesive bonding, crimping, or thelike. The distal end 85 of the coil 80 can be attached to the ribbon 58via the rounded tip portion 69. As discussed above, the rounded tipportion 29 can be made of any suitable material, for example a soldertip, a polymer tip, and the like. In some other embodiments, the distalend 85 may be attached to other structure, for example, a spacer memberor attachment or centering ring, or may be free of attachment.Additionally, the coil 80 can be attached at one or more intermediatepoints, for example, to the centering or attachment ring 65. Forexample, refer to FIG. 8, which shows the coil 80 attached to thecentering or attachment ring 65. The centering ring 65 can function toattach the coil 80 to the guidewire section 16, and can also function tosomewhat maintain the axial and lateral position of the coil 80 relativeto the guidewire section 16. Attachment to the centering ring 64 canalso be performed using any suitable attachment technique, for examplesoldering (e.g. LASER diode soldering), brazing, welding, adhesivebonding, crimping, or the like.

It should be understood, however, that these attachment points are givenby way of example only, and that the coil 80 can be attached atdifferent locations and by using more or fewer attachment points, asdesired, without parting from the spirit and scope of the invention.Additionally, in other embodiments, the coil 80 can be disposed at otherlocations along the length of the guidewire 10, or could extend theentire length of the guidewire 10.

In some embodiments, attachment of the coil 80 at either attachmentpoint 83, at centering or attachment ring 65, or at other locationsalong the length of the guidewire 10 can be achieved using a weldingprocess, for example, LASER or plasma welding. Any of the abovedescribed material, structure, techniques or equipment can be used. Asdescribed above, in LASER welding, a light beam is used to supply thenecessary heat. LASER welding can be beneficial in the processescontemplated by the invention, as the use of a LASER light heat sourcecan provide pinpoint accuracy. It should also be understood that suchLASER welding can also be used to attach other components of theguidewire, as discussed above.

In some embodiments, the connection of the coil 80 at either attachmentpoint 83, or at centering ring 65, can extend around the entirecircumference of the coil 80. In some other embodiments, however, one ormore spaced connection points that do not extend all the way around thecircumference of the coil 80 can be made. The use of certain attachmenttechniques, for example laser welding or laser diode soldering, or thelike, can be useful in making connections around only a portion of thecircumference coil 80 because they tend to allow the accuracy needed tomake such connections. In some embodiments, connections around only aportion of the circumference coil 80 can allow for some desiredcharacteristics, such as increased flexibility of the coil 80.

Additionally, in some embodiments, a transition structure or layer canbe disposed on the distal guidewire section 16 just proximal of theattachment point 83 to provide for a smooth transition between the outersurface of the distal section 16 and the coil 80. Any suitable materialcan be used, for example, an adhesive, a polymer, solder, or other suchmaterial.

The coil 80 may be made of a variety of materials including metals,metal alloys, polymers, and the like, including those described abovewith regard to the guidewire sections 14/16, the connector 18, and theribbon 58. Some examples of some suitable materials include stainlesssteel, such as 304V, 304L, and 316L stainless steel; alloys includingnickel-titanium alloy such as linear elastic or superelastic (i.e.pseudoelastic) nitinol; nickel-chromium alloy; nickel-chromium-ironalloy; cobalt alloy; tungsten or tungsten alloys; MP35-N (having acomposition of about 35% Ni, 35% Co, 20% Cr, 9.75% Mo, a maximum 1% Fe,a maximum 1% Ti, a maximum 0.25% C, a maximum 0.15% Mn, and a maximum0.15% Si); hastelloy; monel 400; inconel 625; or the like; or othersuitable material. In some embodiments, the coil 80 can be made of,coated or plated with, or otherwise include a radiopaque material suchas gold, platinum, tungsten, or the like, or combinations or alloysthereof, or polymer materials including radiopaque materials.Additionally, the coil can include materials or structure to impart adegree of MRI compatibility, as discussed above in relation to theguidewire sections 14/16, the connector 18, and the ribbon 58. Forexample, refer to FIG. 14, which is a cross sectional fragmentary viewof an example coil 590 that can be used in medical devices, such asguidewires, wherein the coil 590 includes an inner portion, layer, orwire 510 that includes or is made of a first material, and an outerportion, layer, or wire 511 that includes or is made of a secondmaterial. For example, the inner portion 510 could be a wire or ribbonas discussed above, and the outer portion 511 could be a coating,cladding, plating, or extrusion of a radiopaque material or an MRIcompatible imaging material, as discussed above.

Referring back to FIG. 1, the coil 80 may be formed of round wire orflat ribbon ranging in dimensions to achieve the desired flexibility. Itcan also be appreciated that other cross-sectional shapes orcombinations of shapes may be utilized without departing from the spiritof the invention. For example, the cross-sectional shape of wires orfilaments used to make the coil may be oval, rectangular, square,triangle, polygonal, and the like, or any suitable shape.

The coil 80 can be wrapped in a helical fashion by conventional windingtechniques. The pitch of adjacent turns of coil 80 may be tightlywrapped so that each turn touches the succeeding turn or the pitch maybe set such that coil 80 is wrapped in an open fashion. In someembodiments, the coil can have a pitch of up to about 0.04 inches, insome embodiments a pitch of up to about 0.02 inches, and in someembodiments, a pitch in the range of about 0.001 to about 0.004 inches.The pitch can be constant throughout the length of the coil 458, or canvary, depending upon the desired characteristics, for exampleflexibility. These changes in coil pitch can be achieved during theinitial winding of the wire, or can be achieved by manipulating the coilafter winding or after attachment to the guidewire. For example, in someembodiments, after attachment of the coil 80 to the guidewire 10, alarger pitch can be achieved on the distal portion of the coil 80 bysimply pulling the coil.

Additionally, in some embodiments, portions or all of the coil 80 caninclude coil windings that are pre-tensioned or pre-loaded duringwrapping, such that each adjacent coil winding is biased against theother adjacent coil windings to form a tight wrap. Such preloading couldbe imparted over portions of, or over the entire length of the coil 80.

The diameter of the coil 80 is preferably sized to fit around and matewith the guidewire 10, and to give the desired characteristics. Thediameter of the coil 80 can be constant or tapered. In some embodiments,the coil 80 is tapered, for example, to mate with a tapered section ofthe guidewire 10, or with other structure. The diameter of the coil 80can also include a taper beyond the distal end of the guidewire section16, as desired.

It will be understood by those of skill in the art and others that abroad variety of materials, dimensions, and structures can be used toconstruct suitable embodiments, depending upon the desiredcharacteristics. The following examples are included by way of exampleonly, and are not intended to be limiting. The coil 80 can be in therange of about 1 to about 20.0 inches long, and is made of rounded wirehaving a diameter of about 0.001 to about 0.004 inches. The coil 80 canhave an outer diameter that is generally constant, and is in the rangeof about 0.01 to about 0.015 inches. The inner diameter of the coil canalso be generally constant, and is in the range of about 0.004 to about0.013 inches. The pitch of the coil 80 can be in the range of about0.0005 to about 0.05 inches.

In FIG. 1, the guidewire 10 also includes an inner coil 90 to form adual coil tip construction. One or more additional inner coils could beincluded in other embodiments. The inner coil 90 is disposed about thedistal end portion 27 of the distal guidewire section 16, and isdisposed within the lumen of the outer coil 80. The inner coil 90 can bemade of the same materials, and have the same general construction andpitch spacing as discussed above with regard to the outer coil 80. Theinner coil, however, would include an outer diameter that allows it tofit within the lumen of the outer coil 80, and in some embodiments, hasan outer diameter that allows it be disposed in a relatively snug ortight fit with the inner diameter of the outer coil 80. In someembodiments, the inner coil 90 can be made of a radiopaque wire, forexample, a platinum/tungsten wire, while the outer coil is made of aless radiopaque material, for example, MP35-N, or vice versa.

In the embodiment shown, the inner coil 90 is disposed about the distalguidewire section 16 from about the middle of the constant diametersection 35, about the ribbon 58, and to a position adjacent the tipportion 69. The coil 90 is attached to the outer coil 80 at proximalattachment point 93 using any suitable attachment technique, for examplesoldering, brazing, welding, adhesive bonding, friction fitting, or thelike. The distal end 97 of the coil 90 is free of attachment. However,in other embodiments, distal end 97 of the coil 90 can be attached tothe outer coil 80, or can be attached to other structure, for example,to the tip portion 69, to a centering or attachment ring, or other suchstructure. In some particular embodiments, the inner coil 90 is attachedonly to the outer coil 80 at one or more attachment points, and isessentially free of any other connection to a core wire, or in somecases, is free of connection to any other structure in the guidewire 10other than the outer coil 80. Additionally, the inner coil 90 can beattached to the outer coil 80 along the entire length of the inner coil90, or only along a portion of the length thereof. For example, in theembodiment shown, the inner coil 90 is attached only at the proximallydisposed attachment point 93. In other embodiments, the coil 90 may beattached using other arrangements, for example, a distally disposedattachment point, or a combination of proximally and distally disposedattachment points. Attachment of the inner coil 90 to the outer coil 80can be achieved using any suitable attachment technique, for examplesoldering (e.g. LASER diode soldering), brazing, welding, adhesivebonding, friction fitting, or the like.

Although attachment of the inner coil 90 to the outer coil 80 can bemade in any suitable manner, as discussed above, in some embodiments,attachment of the inner coil 90 to the outer coil 80 can be achievedusing a welding process, for example, LASER or plasma welding. Any ofthe above described material, structure, techniques or equipment can beused. As described above, in LASER welding, a light beam is used tosupply the necessary heat. LASER welding can be beneficial in theprocesses contemplated by the invention, as the use of a LASER lightheat source can provide pinpoint accuracy. It should also be understoodthat such LASER welding can also be used to attach other components ofthe guidewire, as discussed above.

In some embodiments, the attachment of the inner coil 90 to the outercoil 80 can extend around the entire circumference of the coils 80 and90. In some other embodiments, however, one or more spaced connectionpoints that do not extend all the way around the circumference of thecoils 80 and 90 can be made. The use of certain attachment techniques,for example laser welding or laser diode soldering, or the like, can beuseful in making connections around only a portion of the circumferencecoils 80 and 90 because they tend to allow the accuracy needed to makesuch connections. In some embodiments, connections around only a portionof the circumference of the coils 80 and 90 can allow for some desiredcharacteristics, such as increased flexibility of the coils 80 and 90.

It will be understood by those of skill in the art and others that abroad variety of materials, dimensions, and structures can be used toconstruct suitable embodiments, depending upon the desiredcharacteristics. The following examples are included by way of exampleonly, and are not intended to be limiting. The inner coil 90 can be inthe range of about 0.1 to about 3.0 inches long, and is made of roundedwire having a diameter of about 0.001 to about 0.005 inches. The coil 90can have an outer diameter that is generally constant, and is in therange of about 0.002 to about 0.015 inches. The inner diameter of thecoil can also be generally constant, and is in the range of about 0.001to about 0.008 inches. The pitch of the coil 90 can be in the range ofabout 0.0005 to about 0.04 inches.

As discussed above, in some particular embodiments, the inner coil 90 isattached only to the outer coil 80 at one or more attachment points, andis essentially free of any other connection to a core wire, or in somecases, is free of connection to any other structure in the guidewire 10.Some such embodiments can provide the benefit of one or more additionalcoils, for example coil 90, disposed within the guidewire structurewithout the need to attach such coils to a shaft or core wire. Forexample, in some cases, it may be undesirable to attach additionalstructures to a core or shaft portion of a guidewire due to the possiblechanges in the flexibility or other characteristics at an attachmentpoint. Thus, it may be desirable to avoid such attachment points, andattach any additional coils to a coil that is attached to the core wireor shaft, such as the outer coil 80.

Such an arrangement of an inner coil being attached only to an outercoil could be used in a broad variety of medical devices. For example,refer now to FIG. 9, which is a cross sectional fragmentary view of anexample coil construction 110 that can be used in medical devices whichis very similar to that described above with regard to FIG. 1. The coilconstruction 110 includes an inner coil 190 attached to an outer coil180 at one or more attachment points, for example, attachment point 193.The two coil members 180 and 190 can be made of the same materials, andhave the same general construction and pitch spacing as discussed abovewith regard to the outer coil 80 and inner coil 90. In some otherembodiments, additional coil members could be connected to the outercoil 180. In yet other embodiments, the inner coil 190 could beconfigured for attachment to a medical device, such as a guidewire, andone or more outer coils 180 could be attached to the inner coil 190, andbe essentially free of any other attachment to the medical device. Anysuch coil arrangement could be incorporated into a medical deviceconstruction by attaching only one of the coils to the medical device,while the other coils could be essentially free of any other attachmentother than to the coil that is attached to the medical device. Theattachment of the coil members, for example 180 and 190, to one anothercan be achieved using any suitable attachment technique, for examplesoldering, brazing, welding, adhesive bonding, friction fitting, or thelike, wherein in some embodiments, welding, such as LASER or plasmawelding are particularly used.

Refer now to FIG. 10, which is an alternative embodiment of a coilconstruction 210 including an inner coil 290 attached to an outer coil280 by an intermediate attachment member 285 that interconnects the twocoil members 280 and 290. The two coil members 280 and 290 can be madeof the same materials, and have the same general construction and pitchspacing as discussed above with regard to the outer coil 80 and innercoil 90. The intermediate member 285 can be any structure generallydisposed between and being connected to the two coil members 280 and290. In some embodiments, the intermediate structure 285 can be agenerally tubular structure disposed around inner coil 290, and disposedwithin outer coil 280. However, a broad variety of other structurescould be used. The intermediate structure 285 may be made of a varietyof materials including metals, metal alloys, polymers, and the like,including those described above with regard to the guidewire sections14/16, the connector 18, the ribbon 58, and the coils 180 and 190. Insome embodiments, the intermediate structure 285 can be made of, coatedor plated with, or otherwise include a radiopaque material and/or caninclude materials or structure to impart a degree of MRI compatibility,as discussed above in relation to the guidewire sections 14/16, theconnector 18, the ribbon 58 and the coils 180 and 190. The attachment ofthe coil members, for example 280 and 290, to the intermediate member285 can be achieved using any suitable attachment technique, for examplesoldering, brazing, welding, adhesive bonding, friction fitting, or thelike, wherein in some embodiments, welding, such as LASER or plasmawelding are particularly used.

Refer now to FIG. 11, which shows another alternative coil construction310 including a first coil 390 attached to a second coil 380 at anattachment point 393. The first coil 390 could be adapted or configuredfor attachment to a medical device, for example, for attachment to acore wire or shaft 312 of a guidewire. For example, a proximal portion391 of the first coil 390 could be attached to a core wire or shaft 312,and the core wire or shaft 312 could extend within the lumen of thefirst coil 390. The first coil 390 could include a first constantdiameter portion 381, a tapered portion 383, and a second, narrower,constant diameter portion 385. The second coil 380 could be adapted orconfigured to extend about at least a portion of the tapered portion383, and the second, narrower, constant diameter portion 385. Theattachment point 393 could be adjacent the tapered portion 383.Additionally, the second coil 390 could be essentially free ofattachment to any other portion of the guidewire other than the firstcoil 380. In such embodiments, a distal portion 371 of the second coil390 could be free, or could be attached to the first coil 380 at a pointmore distally than is shown. In other embodiments, however, it iscontemplated that the distal portion 371 of the second coil 390 could beconnected to other structure.

Refer now to FIG. 12, which shows another alternative coil construction410 including a coil 489 including a first inner portion 490 and asecond outer portion 480. In this embodiment, the coil 489 is acontinuous filament that has been wound into the coil constructionincluding the inner and outer portions 490/480. For example, such a coilconstruction can be achieved by first winding a coil filament to createthe inner portion 490 at a desired diameter, and then reversing thewinding of the filament so as to wind the filament around the innerportion 490 to form the outer portion 480. The point of reversal couldform a tip portion 495. Such a winding technique could be accomplishedusing standard coil winding equipment. Additionally, in someembodiments, the two coil portions 480 and 490 can be attached to eachother at one or more point or portion along the length of the coil 490,or along the entire length of the coil 490. Such attachment can be madeusing any suitable attachment technique, for example soldering, brazing,welding, adhesive bonding, friction fitting, or the like, wherein insome embodiments, welding, such as LASER or plasma welding areparticularly used. The two coil portions 480 and 490 can be made of thesame materials, and have the same general construction and pitch spacingas discussed above with regard to the outer coil 80 and inner coil 90.

As seen in FIG. 13, such a coil construction 410 can be incorporatedinto a medical device, for example, for attachment to a core wire orshaft 412 of a guidewire. For example, the tip portion 495 of the coilconstruction 410 could be attached to a distal tip structure 469 of aguidewire, which in turn is attached to a ribbon 458 which in turn isattached to the core wire or shaft 412. In such embodiments, a proximalportion 491 of the outer portion 480 could be free, or could be attachedto other structure, for example, to the core wire or shaft 412 at apoint more proximally than is shown.

Refer now to FIG. 2, which shows a guidewire 10 very similar to thatshown in FIG. 1, wherein like reference numerals indicate similarstructure as discussed above. The proximal/distal guidewire sections14/16, the connection 20, the joint 12, and the tubular connector 18shown in the embodiment of FIG. 2 can also include the same generalconstruction, structure, materials, and methods of construction asdiscussed above with regard to like components in the embodiments ofFIG. 1. The distal tip portion of the guidewire 10 of FIG. 2 is alsovery similar to that shown in FIG. 1, wherein like reference numeralsindicate similar structure. In the embodiment shown in FIG. 2, however,two radiopaque marker members 51 and 53 are attached to the distalguidewire section 16. The markers 51 and 53 are made of, are coated orplated with, or otherwise include radiopaque materials that are capableof producing a relatively bright image on a fluoroscopy screen oranother imaging technique during a medical procedure, as discussedabove. Such markers 51 and 53 can be structures such as bands, coils,and the like, and can be attached to the proximal or distal sections14/16 in any suitable attachment technique, for example, soldering,brazing, welding, adhesive bonding, friction fitting, or the like.Additionally, in some embodiments, the distal guidewire section 16 caninclude constant diameter portions chat are ground or otherwise formedtherein for placement of the markers. Additionally, the position of themarkers 51 and 53 in relation to other structures within the guidewirecan vary widely, depending upon the desired ability to image theguidewire at certain points along the length thereof.

It will be understood by those of skill in the art and others that abroad variety of materials, dimensions, and structures can be used toconstruct suitable embodiments, depending upon the desiredcharacteristics. The following examples are included by way of exampleonly, and are not intended to be limiting. The markers 51 and 53 can becoiled members in the range of about 0.03 to about 2 inches long, and ismade of rounded radiopaque wire (e.g. platinum/tungsten wire) having adiameter of about 0.0005 to about 0.005 inches. The markers 51 and 53can be positioned along the length of the guidewire to achieve thedesired imaging effect. In some embodiments, the inner coil 90 isradiopaque, and is about 2 cm long, the marker 51 is about 0.5 cm long,and is positioned about 1.5 cm from the proximal end of the inner coil90, and the marker 53 is about 0.5 cm long, and is positioned about 1.5cm from the proximal end of the marker 51. It should be understood thata broad variety of marker configurations can be used, including more orfewer marker members.

The embodiment shown in FIG. 2 also includes structure 67 adapted tomate with an extension wire (not shown) disposed near the proximal end25 of the proximal section 14. The structure 67 can include a taperingportion 57 and a constant diameter portion 60. The constant diameterportion 60 can include a threaded portion 70 that is formed therein, orattached thereto. In some embodiments, the treaded portion 70 includes acoiled ribbon or wire that is attached to the constant diameter portion60 using a suitable attachment technique, for example, soldering,brazing, welding, adhesive bonding, friction fitting, or the like.

It should be understood that in some other embodiments, different tipconfigurations can be used. For example, some embodiments can include apolymer jacket tip (optionally covering connection 20) or combination ofa flexible coil tip and/or jacket tip.

For example, refer now to FIG. 15, which shows a guidewire 510 includinga outer sleeve 568 is disposed about the distal end portion 534 of thedistal guidewire section 516. In the embodiment shown, the sleeve 568extends from the tapered region 537 to beyond the distal most portion ofthe ribbon 558, and forms a rounded tip portion 569. In otherembodiments, the sleeve 558 can extend further in a proximal direction,and in some cases can extend over the connection 520, or over theproximal guidewire section 514. In yet other embodiments, the sleeve 568can begin at a point distal of the tapered region 537.

Suitable material for use as the outer sleeve 568 include any materialthat would give the desired strength, flexibility or other desiredcharacteristics. Some suitable materials include polymers, and likematerial. Examples of suitable polymer material include any of a broadvariety of polymers generally known for use as guidewire polymersleeves. The use of a polymer for outer sleeve 568 can serve severalfunctions. The use of a polymer sleeve can improve the flexibilityproperties of the distal portion of the guidewire. Choice of polymersfor the sleeve 568 will vary the flexibility. For example, polymers witha low durometer or hardness will make a very flexible or floppy tip.Conversely, polymers with a high durometer will make a tip which isstiffer. The use of polymers for the sleeve can also provide a moreatraumatic tip for the guide wire. An atraumatic tip is better suitedfor passing through fragile body passages. Finally, a polymer can act asa binder for radiopaque materials, as discussed in more detail below.

In some embodiments, the polymer material used is a thermoplasticpolymer material. Some examples of some suitable materials includepolyurethane, elastomeric polyamides, block polyamide/ethers (such asPebax), silicones, and co-polymers. The sleeve may be a single polymer,multiple layers, or a blend of polymers. By employing careful selectionof materials and processing techniques, thermoplastic, solvent soluble,and thermosetting variants of these materials can be employed to achievethe desired results.

The sleeve 568 can be disposed around and attached to the guidewire 510using any suitable technique for the particular material used. In someembodiments, the sleeve 568 is attached by heating a sleeve of polymermaterial to a temperature until it is reformed around the distalguidewire section 516 and the ribbon 558. In some other embodiments, thesleeve 568 can be attached using heat shrinking techniques. The sleeve568 may be finished, for example, by a centerless grinding or othermethod, to provide the desired diameter and to provide a smooth outersurface.

In some embodiments, the sleeve 568, or portions thereof, can include,or be doped with, radiopaque material to make the sleeve 568, orportions thereof, more visible when using certain imaging techniques,for example, fluoroscopy techniques. Any suitable radiopaque materialknown in the art can be used. Some examples include precious metals,tungsten, barium subcarbonate powder, and the like, and mixturesthereof. In some embodiments, the sleeve 568 can include differentsections having different amounts of loading with radiopaque material.In some embodiments, it is also contemplated that a separate radiopaquemember or a series of radiopaque members, such as radiopaque coils,bands, tubes, or other such structures could be attached to theguidewire 510, and be attached to the guidewire 510 or disposed withinthe sleeve 568.

Some examples of other suitable tip constructions and structures thatcan be used are disclosed in U.S. Pat. Nos. 6,918,882, and 7,074,197,which are incorporated herein by reference.

Additionally, in some embodiments, a coating, for example a lubricious(e.g., hydrophilic) or other type of coating may be applied overportions or all of the medical devices or structures discussed above.For example, such a coating may be applied over portions or all of theguidewire 10, including, for example, guidewire sections 14/16, theconnector 18, the coil 80, the distal tip 69, sleeve 568, or otherportions of the guidewire 10. Hydrophobic coatings such asfluoropolymers, silicones, and the like provide a dry lubricity whichimproves guide wire handling and device exchanges. Lubricious coatingsimprove steerability and improve lesion crossing capability. Suitablelubricious polymers are well known in the art and may includehydrophilic polymers such as, polyarylene oxides, polyvinylpyrolidones,polyvinylalcohols, hydroxy alkyl cellulosics, algins, saccharides,caprolactones, and the like, and mixtures and combinations thereof.Hydrophilic polymers may be blended among themselves or with formulatedamounts of water insoluble compounds (including some polymers) to yieldcoatings with suitable lubricity, bonding, and solubility. Some otherexamples of such coatings and materials and methods used to create suchcoatings can be found in U.S. Pat. Nos. 6,139,510 and 5,772,609, whichare incorporated herein by reference. In some embodiments, the moredistal portion of the guidewire is coated with a hydrophilic polymer asdiscussed above, and the more proximal portions is coated with afluoropolymer, such as polytetrafluroethylene (PTFE).

It should be understood that this disclosure is, in many respects, onlyillustrative. Changes may be made in details, particularly in matters ofshape, size, and arrangement of steps without exceeding the scope of theinvention. For example, alternative structure can be used in connectingthe proximal and distal sections of guidewires. Additionally,alternative tip constructions including a flexible coil tip, a polymerjacket tip, a tip including a coiled safety/shaping wire, or combinationthereof, and other such structure may be placed on the guidewire. Theinvention's scope is, of course, defined in the language in which theappended claims are expressed.

1. A guidewire comprising: an elongate core having a proximal sectionand a distal section, wherein the distal section comprises a linearelastic nickel-titanium alloy and a super elastic nickel-titanium alloy.2. The guidewire of claim 1, wherein the proximal section comprises ametallic material that is different from a nickel-titanium alloy.
 3. Theguidewire of claim 1, wherein the proximal section comprises stainlesssteel.
 4. The guidewire of claim 1, wherein the proximal section and thedistal section are joined by a connector.
 5. The guidewire of claim 4,wherein the connector includes a tubular member.
 6. The guidewire ofclaim 5, wherein the connector includes a plurality of slots formedtherein.
 7. The guidewire of claim 4, wherein the connector includes ametal alloy having a Unified Numbering System (UNS) designation ofN06625.
 8. The guidewire of claim 1, further including a coil memberattached to the distal section of the core, the coil member extendingdistally beyond the core.
 9. The guidewire of claim 8, wherein the coilmember includes a distal end, and further including an atraumatic tipattached to the distal end of the coil member.
 10. The guidewire ofclaim 1, wherein the distal section includes a distal portion, andfurther including a shaping ribbon comprising a non-superelasticmaterial attached to the distal portion of the core.
 11. The guidewireof claim 9, wherein the distal section includes a distal portion, andfurther including a shaping ribbon comprising a non-superelasticmaterial attached to the distal portion of the core, the shaping ribbonbeing disposed inside the coil member and extending distally and beingattached to the atraumatic tip.
 12. A guidewire comprising: a distalcore section comprising a linear elastic nickel-titanium alloy and asuper elastic nickel-titanium alloy; a proximal core section comprisinga metallic material different from a nickel titanium alloy; and aconnector joining the proximal core section to the distal core section.13. The guidewire of claim 12, wherein the proximal section comprisesstainless steel.
 14. The guidewire of claim 12, wherein the distal coresection includes a distal end, and the guidewire further includes anatraumatic tip attached to the distal end of the distal core section.15. The guidewire of claim 14, further including a coil member attachedto the distal core section and to the atraumatic tip.
 16. The guidewireof claim 12, wherein the distal core section includes a distal end, andfurther including a coil member attached to the distal core section andextending distally beyond the distal end of the distal core section, thecoil member including a distal end, and further including an atraumatictip attached to the distal end of the coil member.
 17. The guidewire ofclaim 16, further including a shaping ribbon comprising anon-superelastic material attached to the distal section of the core andextending within the coil member, and attached to the atraumatic tip.18. The guidewire of claim 17, wherein the shaping ribbon comprisesstainless steel.
 19. The guidewire of claim 12, wherein the connectorincludes a tubular member.
 20. A guidewire comprising: a core memberhaving a proximal section and a distal section, the distal sectionincluding a nickel-titanium alloy; wherein the nickel-titanium alloyincludes a combination of super elastic nickel-titanium alloy and linearelastic nickel-titanium alloy; wherein the distal section includes aproximal portion and a distal portion; and wherein at least the proximalportion includes the linear elastic nickel-titanium alloy.
 21. Aguidewire comprising a core having proximal and distal sectionscomprising different materials: the proximal portion including a reduceddiameter distal portion; the distal section including a reduced diameterproximal portion; a hollow coupler connecting the reduced diameterportion of the proximal section to the reduced-diameter portion of thedistal section, wherein the proximal section comprises anon-superelastic alloy; and the distal section includes a combination ofsuper elastic nickel-titanium alloy and linear elastic nickel-titaniumalloy.
 22. The guidewire of claim 21, wherein the distal portionincludes a proximal section and a distal section, and wherein at leastthe proximal section includes the linear elastic nickel-titanium alloy.